In Leonato’s garden, Hero prepares to trick Beatrice into believing that Benedick loves her. With the help of her two waiting women, Margaret and Ursula, she plans to hold a conversation and let Beatrice overhear it—just as Don Pedro, Leonato, and Claudio have done to trick Benedick in the previous scene. Margaret lures Beatrice into the garden, and when Hero and Ursula catch sight of where she is hiding, they begin to talk in loud voices.
Hero tells Ursula that Claudio and Don Pedro have informed her that Benedick is in love with Beatrice. Ursula suggests that Hero tell Beatrice about it, but Hero answers that everybody knows that Beatrice is too full of mockery to listen to any man courting her—Beatrice would merely make fun of both Hero and Benedick and break Benedick’s heart with her witticisms. Therefore, she says, it will be better to let poor Benedick waste away silently from love than expose him to Beatrice’s scorn. Ursula replies by disagreeing with Hero: Hero must be mistaken, because surely Beatrice is too intelligent and sensitive a woman to reject Benedick. After all, everybody knows that Benedick is one of the cleverest and handsomest men in Italy. Hero agrees, and goes off with Ursula to try on her wedding dress.
After Hero and Ursula leave the garden, winking at each other because they know they have caught Beatrice, Beatrice emerges from her hiding place among the trees. Just as Benedick is shocked earlier, Beatrice cannot believe what she has heard at first. Also, like Benedick, she swiftly realizes that it would not be so difficult to “take pity” on her poor suitor and return his love. She knows how worthy Benedick really is and vows to cast off her scorn and pride in order to love him back.
Elsewhere, Don Pedro, Claudio, and Leonato begin to tease Benedick about his decision never to marry. Benedick announces that he has changed, and the others agree; they have noticed that he is much quieter. They say that he must be in love and tease him about it. But Benedick is too subdued even to answer their jokes. He takes Leonato aside to speak with him.
As soon as Claudio and Don Pedro are left alone, Don John approaches them. He tells them that he is trying to protect Don Pedro’s reputation and save Claudio from a bad marriage. Hero is a whore, he says, and Claudio should not marry her. The two are shocked, of course, but Don John immediately offers them proof: he tells them to come with him that night to watch outside Hero’s window where they will see her making love to somebody else. Claudio, already suspicious and paranoid, resolves that if what he sees tonight does indeed prove Hero’s unfaithfulness, he will disgrace her publicly during the wedding ceremony the next day, and Don Pedro vows to assist him. Confused, suspicious, and full of dark thoughts, Claudio and Don Pedro leave with Don John.The trick that Hero and Ursula play upon Beatrice works just as well as the one Don Pedro and Claudio play upon Benedick in the preceding scene, as Beatrice, just as Benedick does, decides to stop resisting marriage and return her supposed pursuer’s love. Clearly, the friends of these two characters know them well. The conversations that Benedick and Beatrice are allowed to overhear are psychologically complicated, appealing to both the characters’ compassion and their pride. Beatrice, like Benedick, cannot help but be flattered to hear that her supposed enemy is in fact dying for love of her. But her sensitive side has been targeted: she is disturbed to hear that he is in such distress, and that she herself is the cause. Moreover, it seems likely that her pride is wounded when she hears people say that she has no compassion and that she would mock a man in love instead of pitying him. Just as Benedick is moved to prove the talkers wrong, so Beatrice seems to be stirred to show that she does have compassion and a heart after all. When Hero says, “Therefore let Benedick, like cover’d fire, / Consume away in sighs, waste inwardly. / It were a better death than die with mocks,” Beatrice is motivated to “save” poor Benedick and also to show that she is not heartless enough to be as cruel as Hero seems to think she is (III.i.77–79).